Strange Noise: need to fix

[sebas54]

Hi, I have a 1988 4.3l gm merc.
Today while at or above 3200rpm I heard a strange noise coming from the engine. It sounded like a rattle/scratching noise, sort like something loose, or rusty metal on metal noise??? Anyway, I was thinking the water circulation pump might be the culprit. Not sure? Any suggestion as to where and what this noise could be are greatly appreciated.

Thank you.

 

[rndn]

Re: Strange Noise: need to fix

It's hard to diagnose the noise however here's a trick to help you narrow down the culprit. Take a hardwood broom handle and while the engine is running touch the hardwood to various non-moving engine parts. While doind this cup your hand around the other end of the stick and hold it up to your ear. The hardwood magnifies the sound and move it around onto various non-moving engine parts until you hear the noise the loudest. If you think it's the water pump, place it on the non-moving part of the pump and you should really hear the difference.
This only works on a running engine so if you do this at home, please make sure you follow the proper muff procedures. It's important to hold the other end of the handle up very close to your ear while cupping the outside of the stick for it to work . You're basically trapping the noise coming up from the stick and focusing it to your ear. You'll be amazed at how well this very simple trick works.

 

[imported_TheMan]

Re: Strange Noise: need to fix

Unfortunately that description is pretty vag and likerndn says, it is pretty hard to diagnose without being there. Have you tried the basics, like making sure your flame arrestor is fastened down tightly and your power steering pump + alternator are properly installed?

My power steering pump isn't riding completely right and it clicks a bit at high speeds. I need another bolt for it.

 

[Bondo]

Re: Strange Noise: need to fix

Ayuh,.....

Sounds like Detonation,......

Is the Timing set Right,....??
Fuel Filters Clean,..??

You can turn a Motor into an Anchor in just a few minutes if it Is..........

 

[sebas54]

Re: Strange Noise: need to fix

Hi, Thanks for all the replies.

Bond Do, How do I check the timing. I payed some *** last year $200 last year to set the timing but I suspect that it was not done right. There is no harmonic balancer to be found.

I am going to buy a timing light.
What do I do. Do I hook up the light to the spark plug wire #2 and point and read?? Please let me know what the degree is supposed to be set at.


Thank you.